Cyanine dyestuffs



Patented May 31, 1949 v UNITED STATES PATENT OFFICE CYANINE DYESTUFFSJohn David Kendall and Frank Peter Doyle, Ilford, England, assignors toIlford Limited, Ilford, England, a- British company No Drawing.Application January 21, 1948, Serial No. 3,561. In Great Britain January24, 1947 '7 Claims. (Cl. 260-240) 1 2 This invention relates to theproduction of cyclic homologues such as those of the benzene,symmetrical cyanine dyestuffs. naphthalene, acenaphthene and anthracenese- According to the present invention symmetrical ries, pyridine andits polycyclic homologues such cyanine dyestuffs are prepared bycondensing as quinoline and ocand ,6-naphthoquino1ines,lepone molecularequivalent of cyanacetic acid with idines, indolenines, diazines (e. g.thio;3[3'-diaat least two molecular equivalents of an alkyl zole),oxazolines, thiazol-ines and selenazolines. or aralkyl quaternary saltof a five-membered or The polycyclic compounds of these series maysiX-membered heterocyclic nitrogen compound also be substituted in thecarbocyclic rings with having in a or position to the quaternarynitroone or more groups such as alkyl, aryl, amino, hygen atom athioether or selenoether group (indroxy, alkoxy methylene-dioxy groupsor by halcluding an aryl, alkyl, or aralkyl thioether or ogen atoms.selenoether group) separated from the hetero- The acid radicle X may be,for'example', halide, cyclic nucleus by a vinyl or butadienyl group), orsulphate or p-toluene sulphonate. a --(CH=CH)m NHz group Where m is 1, 2or Where R is an alkyl group it may be a lower 3 (including N-acyl,N-aryl and N-acylaryl subalkyl group, e. g. methyl, ethyl or propyl,which stituted groups of this type). is generally preferable, or it maybe a higher For the sake of convenience the expression alkyl group. Wh eR s n a yl g p it -thioether vinyl and selenoether vinyl types of ay beb yl'o p y y group will be understood to mean the various 0 Thefollowing examples, in which the parts ar classes of such groupsreferred to above, and the by We l se v to ustrate the invention:expression amino vinyl type of group will be EXAMPLE 1 understood tomean the various groups of the formula (CH CH)m NH2 and substitutionderivatives referred to above.

Bis 2 [3 methyl benzthiazole] 'y-cyomo pentamethine-cyamne p-toluenesulphonate' The reaction is preferably effected in the DIGS- 20 parts of2(w'ethylthiovinyl)benzthiazole ence of a basic condensing agent, e. g.pyridine, metho-p-tol'uene sulphonate, 2.1 parts of cyantriethylamine orsodium acetate in ethyl alcohol. acetic acid and 200 parts of pyridinewere heated The course of the reaction may be typified by for minutes onthe waterbath, and after coolthe following example: ing and dilutionwith ethyl alcohol the thick The products thus conform to the generalsuspension was filtered and the dyestufi washed formula: with ethylalcohol, benzene and water. Recrystallisation from methyl alcohol gaveblue needles, I l M. Pt. 262 C. (with decomposition). The cor Iresponding iodide melted at 265 C, (with de- R X R composition) where Dis the residue of a five-membered or EXAMPLE 2 six-membered heterocyclicn1trogen nucleus, R is an alkyl or aralkyl group and X is an acidBzs'2[3"ethyl beftzihwzolpl 7 cyemopentameradicle, n is nought or oneand m is 1, 2 or 8. thmecyanmeqodlde The ring system D of theheterocyclic nitro- 90 parts of 2(w-acetanilido vinyDbenzthiazole gencompound may be, for example, selected from ethiodide, 8.5 parts ofcyanacetic acid and 400 thiazoles, oxazoles, selenazoles and theirpolyparts of pyridine were refluxed for 1 hour and the precipitateddyestufi separated by filtration and washed. Recrystallisation frommethyl alcohol gave tiny green crystals, M. Pt. 282 C.

(with decomposition).

EXAMPLE 3 Bis-2- [1 .2.3.trimethyl indolemnel-y-cyonopentamethine-cyanine-iodide 42 parts of 2(w-ethylthiovinyl)-3.3-dimethyl indolenine metho-p-toluene sulphonate, 4.3 parts ofcyanacetic acid and 250 parts of pyridine were refluxed for 30 minutesand the crimson solution poured into aqueous potassium iodide solution.Cooling and dilution gave a tarry material which, when boiled out withbenzene, yielded green crystals of the desired dyestuff. Purificationwas effected by dissolving the crystals in the minimum of methylalcohol, filterin and diluting the filtrate with ether, to giveglittering bluegreen crystals, M. Pt. 256 C. (decomp.).

EXAMPLE 4 Bis-Z- [1 -ethyl quinoline]-'y-cyano-pentamethine-cyanine-iodide 2 (w-ethylthio-vinyl) -quinolineetho-p-toluene sulphonate (the crude yield obtained by the methoddescribed in B. P. 555,935 from 69 parts quinaldine etho-p-toluenesulphonate, and 40 parts triethyl trithio-ortho-formate in 500 partsacetic anhydride) was refluxed with 8.5 parts cyanacetic acid in 300parts of pyridine for 30 minutes and the blue solution poured intoaqueous potassium iodide solution. The dyestufl which crystallised outwas filtered, washed and recrystallised from methyl alcohol to giveglitether-vinyl, selenoether-viny1 and amino-vinyl groups.

2. A process according to claim 1 wherein the reaction is efiected inthe presence of a basic condensing agent.

3. A dyestufi of the general formula:

:---D----: ON ----n--- N= oH-H ,.=o-cH=oH-e=cH-oH=coH=oH)r1 1 R X i iwherein D is a residue selected from the class consisting of S-memberedand G-membered heterocyclic nitrogen nuclei, R is a group selected fromthe class consisting of alkyl and aralkyl groups, X is an acid radicleand n is selected from the class consisting of 0 and 1.

4. A dyestuff of the general formula:

wherein D is a residue selected from the class consisting of 5-memberedand G-membered heterocyclic nitrogen nuclei, R. is a lower alkyl groups,X is an acid radicle and n is selected from the class consisting of 0and 1.

5. A compound of the formula:

CH SOaCgHlCHS 6. A compound of the formula:

JOHN DAVID KENDALL. FRANK PETER DOYLE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,153,169 Brooker Apr. 4, 19392,345,094 Brooker Mar. 26, 1944 FOREIGN PATENTS Number Country Date431,141 Great Britain June 24. 1935

